How do you address someone in Islam?

Use the phrase “As-Salam-u-Alaikum” (“Peace be unto you”). This is pronounced “as-saa-laam-muu-ah-lay-kum.” You might also choose to use the longer greeting of “As-Salam-u-Alaikum wa-rahmatullahi wa-barakatuh” (“Peace be unto you and so may the mercy of Allah and his blessings”).